Down pipe

[honest_jim]

On the standard turbo i noticed that there is a seperate plate bolted over the waste gate exit. Im am about to start putting together a down pipe to mate up with the rest of my exhaust (2.5"). Would it be ok to remove this plate and route the waste gate gasses in to the main exhaust furthure down. Would this cause any probs or give an positive gains. It dosent look like a good thing to me have the plate bolted on there.

Also does any one have any pics of down pipes they have made or had made. I was thinking of maing mine 2.5" to match the rest of the system any advice would be great thanks.

[mrcordial]

Hey mate,

The wastegate plate on the exhaust side has an opening that allows the gasses to join into the exhaust via a small opening.

I'd think that using just one flange would have some sort of benifit but very minimal? just more free flowing i'd think.

[honest_jim]

i think i'll give it a try anyway might just run the wastegate gasses down under the car and not bother joining the pipe up to the rest of the exhaust and see what happens.

[toysrus]

What happens is very loud noises appear out of no where once/almost as you reach full boost.....to get the full benefits, you would seal of the hole which allow the gases esaping past the wastegate flap back into the turbine exit hole so that all the gases from the wastegate only exit through your seperate pipe. This allows the better flow of the main exhaust gases into your dump-pipe and should result in your torque and power band shifting a little to the left of your rpm range aKa sooner :P

[honest_jim]

A loud noise eh?? sound like it might be funny. I'll have to have a look when i take it all apart. Might be able to extend the small pipe in to the wastegate part of the turbo or something to try block off the other hole??

I'll let you all know how it goes.

[jakobsladderz]

Exhaust would always be coming out the second pipe because there's a connection between the main outlet and the WG outlet. You'd somehow need to block the connection first otherwise your 'open-to-the-air' wastegate pipe would make a lot of noise all the time..

[honest_jim]

Damn never even thourght og it that way round... well i'll have to see might just have to connect the smaller pipe up to the main dump pie then.

[toysrus]

Ok, this is the way I'm going to do mine.

On the main outler, ie the 2 1/2" size hole, I am going to have it bored about 1.5mm extra and then have a 2 1/2" Exhaust pipe to the length of how far the oversizing was bored down and basically squeeze it in, essentially making a sleeve which blocks the passage between the Turbine outlet and Wastegate.

Now the Wastegate WILL ONLY make noise when close to your Boost limit and once you hit your Boost limit.

[iXNAY]

sounds like u got the plan should work if all goes to plan.

[redzone]

in my opinion and experience make the main dump pipe off the back of the turbine outlet from 3 inch mandrel bent piping. even tho its bigger than the turbine outlet, it is still going to work better than a 2.5 inch pipe which is roughly the same size, this is because the exhaust gases are so hot there that any size increase will only be a benefit.

it decreases the back pressure in the system and lets the turbo spool up sooner, u can put a reducer and a flange to meet up to ur 2.5 inch system most likely around the bellhousing area! i had a 2.5 inch press bent system on mine, dump included, the difference between that and my new 3 inch mandrel system including dump pipe was like chalk and cheese! and the previous one wasn`t that bad!!

and i`d recommend running the wastegate outlet pipe back into the system about a metre back from the turbo, when the gas has had time 2 cool down enough. u WILL get sick of the sound from the screamer pipe in a REAL hurry! gets annoying! :beer

[Eurotrash]

I have a mandrel 3 inch stainless down pipe (and to the tail pipe as a matter of fact) with a pipe from the wastegate where the backing plate was that joins the main system. The only thing I notice is the sound I liken to a turbo prop aircraft starting up.

[coop1er]

Whilst wandering around the local wrecking yard, looking for bits and
pieces, I came across this:



This was on a JA. It is a standard tc06 with 3" exhaust and 1.5" screamer
and exhaust manifold. The turbo feels good, no play in it. Exhaust
manifold has no cracks. Strangely though, the 1.5" screamer pipe is
welded to the standard wastegate plate but the plate only has a 10mm
hole in it. Still not a bad buy for $70 I reckon. :)

[fr335tyl3r]

You have JA starions at wrecking yards that havent been reduced to a stripped chassis?

Lucky!

[TOMSUN]

Bargain...

Let us know how it goes :D

[13secJA]

I found with my car running the factory waste gate setup as soon as the waste gate opened fully it caused so much turbulents behind the turbine wheel you could feel the cars power drop off(around 4500rpm) Once the w\g was open it was a very slow climb through the rest of the rev range. So I sleeved the exhaust housing to cover the w\g port with a piece of stainless steel pipe, now the w\g vents out of a screamer pipe system. It’s not that loud and it made a huge difference. I have some pics somewhere I’ll find them and post them if you like.